The invention relates to the field of seabed-to-surface installations of the hybrid tower type making it possible to carry fluids and in particular hydrocarbons from a seabed installation connected to wellheads to a surface installation.
Normally, hybrid towers comprise at least one riser, usually rigid, suspended below the surface from a float and anchored in the seabed, and at least one flexible pipe which extends in catenary suspension between the riser, at the float, and a surface installation. The riser and the flexible pipe are then connected by means of an underwater connection installation.
The underwater connection installation comprises a frame forming a post which is kept below the surface by the float formed of usually cylindrical air tanks. Said post extends along these cylindrical air tanks and it has a base at the bottom end of the tanks in order to suspend said riser, and a portion overhanging said base at the top end of the tanks. It also comprises at least one gooseneck pipe, which has an inlet end secured to the base of the post and a curved free outlet end which extends into the top post portion and which is curved toward the bottom end of the tanks. The curved free ends of the gooseneck pipes are engaged in a first inclined plane and are terminated by a first coupling which has a first centering lip. Moreover, said installation comprises at least one coupling endpiece suitable for being mounted at one end of a flexible pipe. The coupling endpiece comprises a second coupling having a second centering lip. Moreover, the coupling endpiece is installed on a second inclined plane, which is capable of being installed on the post by means of a diver and then of being guided in translation toward the first inclined plane in order to coaxially guide said couplings toward one another and in order to bring the first and second lips into contact with one another. Then, by installing locking means on the couplings, the seal is provided between the riser and the flexible pipe. Reference can be made notably to document FR 2 497 264 which describes a connection installation of this type.
A major drawback of the aforementioned connection installations is that they require human intervention below the surface to make the connection.
Therefore, a problem that arises and that the present invention aims to solve is to provide a connection installation which makes it possible to make a sealed connection below the surface between a riser and a flexible pipe while avoiding a human intervention below the surface.